On the Meine Kalender page, select a calendar you wish enable alarms for.
Click Bearbeiten.
Click the tab Alarme and adjust the alarm settings as you like.
Click Speichern.
On the home screen of the device, tap Calendar.
Turn the device to portrait orientation, scroll down to Calendar and tap it.
Look for the calendar you wish to unsubscribe and tap on the icon beside it.
Make sure Event Alerts is ON. Finally, tap Done in the top right corner.
Updated 8 Feb 2023